1. Field of the Invention
This invention relates to a pre-fabricated, foldable, portable building which retracts to a parallelepiped box-like structure having an external shape, dimensions, handling, securing, and external load capacity which are compatible to most series 1AA, 1BB, and 1CC I.S.O. freight containers, or to a standard "high cube" shipping container.
2. Discussion Of the Prior Art
Pre-fabricated, foldable, portable building structures have been developed to enable shipment of structures in a collapsed form while facilitating the erection of those buildings. One objective in developing pre-fabricated, foldable, portable buildings is to provide for maximum square footage of erected structure while retaining a minimum volume of the structure in its collapsed form for shipping purposes. This avoids the unnecessary transportation of air volume within the structure, resulting in more economical transportation of such structures. At the same time, hingedly joining components of the structure to fold when collapsed facilitates erection of these structures at the erection site by unskilled labour at considerable cost and time saving.
The successful development and introduction of containerized transportation, involving the loading of fixed dimension containers aboard land, sea, and air modes of transportation specially adapted for standard container sizes, has provided considerable cost benefit and generally provides safer and quicker world wide freight transportation. The I.S.O. freight containers have been universally adopted by most modern modes of transportation, and practically every country in the world is now capable of handling and delivering such containers, making it possible to ship I.S.O. freight containers to practically any destination in the world.
Given the benefits associated with containerized transportation, the development of a pre-fabricated, foldable, portable building which is collapsible to fit within the outside dimensions of shipping containers meeting I.S.O standards is desirable. However, one problem associated with the development of a pre-fabricated, foldable, portable building which is collapsible to fit within the outside dimensions of an I.S.O. shipping container is the fact that the most popular I.S.O. shipping containers have an overall height of approximately eight and one-half feet. At the same time, it is desirable to provide an erected portable building having an interior ceiling height of at least seven and one-half feet from the floor, dictated by basic anthropometric and related construction standards. The difficulty arises with the inclusion of a sloping roof to such a building. In order to accommodate trusses which support a sloping roof of desired pitch in a building having a ceiling height of at least seven and one-half feet and a floor assembly thickness of at least six inches, an overall height in excess of eight and one-half feet must be accommodated, thereby exceeding standard I.S.O. container height. The distance between the ceiling and the peak of the roof extends the height substantially greater than eight and one-half feet and thereby greater than the maximum height dimensions of a standard shipping container.
A portable building having a sloping roof with extending roof trusses is disclosed in U.S. Pat. No. 3,348,344 of L. Tatevossian. The Tatevossian building provides for a rigid central roof extension above the ceiling to accommodate the trusses to support a sloping roof. If the ceiling height of the structure is at least seven and one-half feet, the upwardly extending trusses and floor thickness will make the height of the collapsed building substantially greater than the eight and one-half foot maximum height of an ISO shipping container. The apex of the upwardly extending trusses form the upper edge of the main support. This upper edge is substantially higher than the upper edges of the side wall panels which support the ceiling panels.
Accordingly, there exists a need for a pre-fabricated, foldable, portable building which, in its collapsed, folded position, is of an external shape, dimension and is appropriately configured to be compatible with series 1AA, 1BB and 1CC ISO freight containers, or to standard "high cube" shipping containers. This permits transportation and freight handling by almost every modern intermodal mode of freight transportation, to any destination, at a reasonable cost. At the same time, the foldable nature of such buildings permits ease of assembly at the site in a short time, with conventional, manually operated tools, without the need for skilled labour or heavy equipment. Because the building structure makes up most of the walls and the floor of the collapsed container-sized building, after installation, there is little or no residual waste materials or packaging and no returnable components or containers, which further significantly reduces transportation and handling costs and load on the environment.